No. 518] SHORTER ARTICLES AND DISCUSSION 123 



and facts in his reference to the real contributions which Mendel 

 has made. "The really important Mendelian contribution be- 

 ing that certain definite characters (such as have according to 

 my belief, rather general processes as a basis) of different races 

 may be combined to form new fixed races" (with which we all 

 agree). "The establishment of this last fact has been most 

 commonly considered by Mendel ians on the one hand a conse- 

 quence of the laws of dominance ( !) and segregation, and on the 

 other hand as a strong argument for a 'representative particle' 

 basis for these two sets of phenomena." There are some Men- 

 delians who really do not believe there is any law of dominance, 

 and there are many more Mendelians who do not believe in a 

 representative particle theory at all. Here, as elsewhere 

 throughout his paper. Kiddle confuses Mendelism with de 

 Vriesianism and Weismannism. The following quotation ap- 

 plies only to de Vriesians and Weismannians, not to Mendelians: 

 "With an eye seeing only [xirticlrs and a speech only symbol- 

 izing them there is no such a thing as the study of a process 

 possible." Castle in his work on rabbits has no such particles 

 in his mind's eye; his terminology does not imply them; he 

 merely describes the facts of color inheritance. 



While in this review of Riddle's most interesting paper the 



every point, he is quite in sympathy with Kiddle's point of view. 

 The thing he has tried to combat is Riddle's confusion of Men- 

 delian facts with de Vriesian hypotheses. The writer hopes in 

 the near future to be able to present a theory of Mendelian 

 inheritance which is independent of the idea of unit characters 

 and wholly independent of the idea of discontinuous variation. 



W. J. Spillman. 



